How police cracked the Tiahleigh Palmer murder case wide open

Rick and Julene Thorburn portrayed themselves as the perfect foster family – a happily married couple with two talented teenage sons, Trent and Josh, living on an idyllic property near Brisbane.

A close, caring family unit that welcomed 12-year-old foster child Tiahleigh Palmer with open arms.

But tragically as the young school girl discovered, behind closed doors the Thorburns were the epitome of evil.

‘Betrayal’ airs tonight on 60 Minutes after The Voice on Channel 9. For more on 60 Minutes, head to the 60 Minutes website.

In a bid to cover up his son’s sexual abuse of the primary school student, Rick Thorburn murdered Tiahleigh in cold blood before dumping her body in a nearby river.

A relentless police investigation has seen the Thornburn's façade crumble and every lie exposed. Picture: 60 Minutes (60 Minutes)

The Thorburn three – Julene, Trent and Josh – went to great lengths to keep their patriarch’s evil secret, lying time and time again under oath. But a relentless police investigation saw their façade crumble and every lie exposed.

In a landmark exclusive tonight on 60 Minutes, police take reporter Tara Brown inside the Tiahleigh Palmer murder case to reveal the covert strategy used to break the family’s pact of secrecy.

“Cindy is absolutely traumatised and devastated by the loss of her daughter,” Brown said.

“And within that loss there is a sense of guilt. That the choices that she made in the past may have placed her daughter there.

“She, for very good reasons, wasn’t able to care for Tiahleigh – though was desperate to get her back, she tells me.

“So there’s this terrible feeling of some sense of responsibility, but also a lack of understanding of how this could happen.”

Murder, incest, intimidation and lies are at the centre of this haunting story.

“The other side of that of course is that this is a very isolated home. If nobody cares for you inside the place – nobody’s looking out for you, nobody loves you – then you are all alone." Picture: 60 Minutes (60 Minutes)

But as Brown reveals, so too is the bewildering question of how an innocent schoolgirl in desperate need of a safe and loving family could slip through the cracks and become a victim of the child safety system in the most horrendous way.

“I think the most confronting aspect of this story was that when you look at the Thorburn property, on the surface it is the idyllic place to bring up children,” Brown said.

“There are horses, there are animals, there is space to play.

“The other side of that of course is that this is a very isolated home. If nobody cares for you inside the place – nobody’s looking out for you, nobody loves you – then you are all alone.

“And I can’t imagine how terrifying that must have been for that little girl the night that she was murdered. That there was no one there but the man who was going to hurt her."